Scientific Name: Microbryum vlassovii
Taxonomy Group: Mosses
Range: British Columbia
Last COSEWIC Assessment: November 2016
Last COSEWIC Designation: Endangered
SARA Status: Schedule 1, Endangered
Image of Nugget Moss
Nugget Moss is a small moss, less than 2 mm tall, that grows as erect individuals or in small, scattered patches. The leaves are light green to yellow-green or golden green, about 1 mm long, and usually somewhat concave or prow-shaped above. The leaf midrib is pale brown and often wider near the apex than below. In this species, both male and female structures are present on each plant. Sporophytes, which produce spores, mature in late winter or in spring and are immersed in the leaves. The spores, which germinate and grow into new plants, are held in a rounded capsule with a tiny point at the top. Unlike most mosses, the capsules of Nugget Moss do not have a lid that opens to release the spores. Instead, the capsule wall disintegrates as conditions dry into the summer.
Distribution and Population
Nugget Moss is extremely rare in western North America, where it has been reported from only southern British Columbia and California. It also occurs in western Eurasia, where it is rare. In Canada, it has been reported from two locations in south-central British Columbia (east of Kamloops and on the east side of Penticton). Only the Penticton population was confirmed during the most recent survey. No precise information is available on population condition or trends for Nugget Moss in British Columbia. Only one population consisting of eight individuals in two small patches was recently re-located. The extremely small population makes Nugget Moss particularly vulnerable.
In British Columbia, Nugget Moss is restricted to undisturbed, exposed, compact silts and clays on post-glacial lacustrine banks in semi-arid grassland and steppe environments where vegetation is sparse. Nugget Moss grows on the partially shaded or highly exposed steep slopes of these banks, where few other moss species are able to grow.
Nugget Moss is inconspicuous and grows as individuals or in small, scattered patches on compact, clay-rich soil. Although production of sporophytes is common in Canadian populations, only immature capsules have been observed to date. It is likely that this species needs a relatively prolonged wet spring to enable the spores to mature. Spores, if produced, are probably of importance in the short-range dispersal of this species. Nugget Moss may be a perennial species, since tuber-like structures (absorbent root-like filaments) have been observed on the rhizoids. These “tubers” rich in reserve foods may also be of importance in the survival of the species.
The habitat of this species is threatened by road construction and maintenance. Both reported sites in British Columbia are adjacent to roadways and road expansion. Recreational hiking is also a threat, since both sites are near residential areas.
Federal ProtectionThe Nugget Moss is protected under the federal Species at Risk Act (SARA). More information about SARA, including how it protects individual species, is available in the Species at Risk Act: A Guide.
Nugget Moss is not protected under any provincial legislation in British Columbia.
Provincial and Territorial Protection
Status of Recovery Planning
Recovery Strategies :
Name Recovery Strategy for the Nugget Moss (Microbryum vlassovii) in Canada
Status Final posting on SAR registry
PLEASE NOTE: Not all COSEWIC reports are currently available on the SARA Public Registry. Most of the reports not yet available are status reports for species assessed by COSEWIC prior to May 2002. Other COSEWIC reports not yet available may include those species assessed as Extinct, Data Deficient or Not at Risk. In the meantime, they are available on request from the COSEWIC Secretariat.
8 record(s) found.
- COSEWIC Status Reports (1 record(s) found.)
- COSEWIC Assessments (1 record(s) found.)
- Response Statements (1 record(s) found.)
- Recovery Strategies (1 record(s) found.)
- Orders (2 record(s) found.)
- COSEWIC Annual Reports (1 record(s) found.)
- Consultation Documents (1 record(s) found.)
COSEWIC Status Reports
COSEWIC Annual Reports
COSEWIC Annual Report - 2007 (2007)2007 Annual Report to the The Minister of the Environment and the Canadian Endangered Species Conservation Council (CESCC) from the Committee on the Status of Endangered Wildlife in Canada.
- Date modified: